Management of hospital outbreaks of gastro-enteritis due to small round structured viruses

Management of hospital outbreaks of gastro-enteritis due to small round structured viruses

Management of hospital outbreaks of gastro-enteritis due to small round structured viruses

Small round structured viruses (SRSVs, Norwalk-like viruses, NLVs) are the most commoncause of outbreaks of gastro-enteritis in hospitals and also cause outbreaks in other settings such as schools,hotels, nursing homes and cruise ships. Hospital outbreaks often lead to ward closure and major disruptionin hospital activity. Outbreaks usually affect both patients and staff, sometimes with attack rates in excess of50%. For this reason, staff shortages can be severe, particularly if several wards are involved at the sametime. SRSVs may be spread by several routes: faecal–oral; vomiting/aerosols; food and water. Viruses maybe introduced into the ward environment by any of these routes and then propagated by person-to-personspread. In an outbreak setting, the diagnosis can usually be made rapidly and confidently on clinical andepidemiological grounds, particularly if vomiting is a prominent symptom. By the time an SRSV outbreakhas been recognized at ward level, most susceptible individuals will have been exposed to the virus andinfection control efforts must prioritize the prevention of spread of infection to other clinical areas bycontainment of infected/exposed individuals (especially the prevention of patient and staff movements toother areas), hand-hygiene and effective environmental decontamination.This report of the Public Health Laboratory Service Viral Gastro-enteritis Working Group reviews the epidemiologyof outbreaks of infection due to SRSVs and makes recommendations for their management in thehospital setting. The basic principles which underpin these recommendations will also be applicable to themanagement of some community-based institutional outbreaks.

Abstract

Small round structured viruses (SRSVs, Norwalk-like viruses, NLVs) are the most commoncause of outbreaks of gastro-enteritis in hospitals and also cause outbreaks in other settings such as schools,hotels, nursing homes and cruise ships. Hospital outbreaks often lead to ward closure and major disruptionin hospital activity. Outbreaks usually affect both patients and staff, sometimes with attack rates in excess of50%. For this reason, staff shortages can be severe, particularly if several wards are involved at the sametime. SRSVs may be spread by several routes: faecal–oral; vomiting/aerosols; food and water. Viruses maybe introduced into the ward environment by any of these routes and then propagated by person-to-personspread. In an outbreak setting, the diagnosis can usually be made rapidly and confidently on clinical andepidemiological grounds, particularly if vomiting is a prominent symptom. By the time an SRSV outbreakhas been recognized at ward level, most susceptible individuals will have been exposed to the virus andinfection control efforts must prioritize the prevention of spread of infection to other clinical areas bycontainment of infected/exposed individuals (especially the prevention of patient and staff movements toother areas), hand-hygiene and effective environmental decontamination.This report of the Public Health Laboratory Service Viral Gastro-enteritis Working Group reviews the epidemiologyof outbreaks of infection due to SRSVs and makes recommendations for their management in thehospital setting. The basic principles which underpin these recommendations will also be applicable to themanagement of some community-based institutional outbreaks.